A Shinobi Wench Hammer is a move during sexual intercourse where the lights are turned out and the male rams the female from the darkness, so hard that she should climax upon landing. Usually performed towards the end of a sexual occurance as a pièce de résistance. It can be executed from infront or behind of a woman. If executed correctly from the rear, it may lead to a Wench Hammer Mudslide

...Silence... *scream of fright then pleasure* "You've just been Shinobi Wench Hammered baby, now lick this mudpie off my sack!"